import errno
import importlib
import inspect
import json
import logging
import pkgutil
import struct
import sys

import pytest

from ..deviceconfig import DeviceConfig
from ..exceptions import SmartDeviceException
from ..protocol import (
    BaseTransport,
    TPLinkProtocol,
    TPLinkSmartHomeProtocol,
    _XorTransport,
)


@pytest.mark.parametrize("retry_count", [1, 3, 5])
async def test_protocol_retries(mocker, retry_count):
    def aio_mock_writer(_, __):
        reader = mocker.patch("asyncio.StreamReader")
        writer = mocker.patch("asyncio.StreamWriter")

        mocker.patch(
            "asyncio.StreamWriter.write", side_effect=Exception("dummy exception")
        )

        return reader, writer

    conn = mocker.patch("asyncio.open_connection", side_effect=aio_mock_writer)
    config = DeviceConfig("127.0.0.1")
    with pytest.raises(SmartDeviceException):
        await TPLinkSmartHomeProtocol(transport=_XorTransport(config=config)).query(
            {}, retry_count=retry_count
        )

    assert conn.call_count == retry_count + 1


async def test_protocol_no_retry_on_unreachable(mocker):
    conn = mocker.patch(
        "asyncio.open_connection",
        side_effect=OSError(errno.EHOSTUNREACH, "No route to host"),
    )
    config = DeviceConfig("127.0.0.1")
    with pytest.raises(SmartDeviceException):
        await TPLinkSmartHomeProtocol(transport=_XorTransport(config=config)).query(
            {}, retry_count=5
        )

    assert conn.call_count == 1


async def test_protocol_no_retry_connection_refused(mocker):
    conn = mocker.patch(
        "asyncio.open_connection",
        side_effect=ConnectionRefusedError,
    )
    config = DeviceConfig("127.0.0.1")
    with pytest.raises(SmartDeviceException):
        await TPLinkSmartHomeProtocol(transport=_XorTransport(config=config)).query(
            {}, retry_count=5
        )

    assert conn.call_count == 1


async def test_protocol_retry_recoverable_error(mocker):
    conn = mocker.patch(
        "asyncio.open_connection",
        side_effect=OSError(errno.ECONNRESET, "Connection reset by peer"),
    )
    config = DeviceConfig("127.0.0.1")
    with pytest.raises(SmartDeviceException):
        await TPLinkSmartHomeProtocol(transport=_XorTransport(config=config)).query(
            {}, retry_count=5
        )

    assert conn.call_count == 6


@pytest.mark.parametrize("retry_count", [1, 3, 5])
async def test_protocol_reconnect(mocker, retry_count):
    remaining = retry_count
    encrypted = TPLinkSmartHomeProtocol.encrypt('{"great":"success"}')[
        TPLinkSmartHomeProtocol.BLOCK_SIZE :
    ]

    def _fail_one_less_than_retry_count(*_):
        nonlocal remaining
        remaining -= 1
        if remaining:
            raise Exception("Simulated write failure")

    async def _mock_read(byte_count):
        nonlocal encrypted
        if byte_count == TPLinkSmartHomeProtocol.BLOCK_SIZE:
            return struct.pack(">I", len(encrypted))
        if byte_count == len(encrypted):
            return encrypted

        raise ValueError(f"No mock for {byte_count}")

    def aio_mock_writer(_, __):
        reader = mocker.patch("asyncio.StreamReader")
        writer = mocker.patch("asyncio.StreamWriter")
        mocker.patch.object(writer, "write", _fail_one_less_than_retry_count)
        mocker.patch.object(reader, "readexactly", _mock_read)
        return reader, writer

    config = DeviceConfig("127.0.0.1")
    protocol = TPLinkSmartHomeProtocol(transport=_XorTransport(config=config))
    mocker.patch("asyncio.open_connection", side_effect=aio_mock_writer)
    response = await protocol.query({}, retry_count=retry_count)
    assert response == {"great": "success"}


@pytest.mark.parametrize("log_level", [logging.WARNING, logging.DEBUG])
async def test_protocol_logging(mocker, caplog, log_level):
    caplog.set_level(log_level)
    logging.getLogger("kasa").setLevel(log_level)
    encrypted = TPLinkSmartHomeProtocol.encrypt('{"great":"success"}')[
        TPLinkSmartHomeProtocol.BLOCK_SIZE :
    ]

    async def _mock_read(byte_count):
        nonlocal encrypted
        if byte_count == TPLinkSmartHomeProtocol.BLOCK_SIZE:
            return struct.pack(">I", len(encrypted))
        if byte_count == len(encrypted):
            return encrypted
        raise ValueError(f"No mock for {byte_count}")

    def aio_mock_writer(_, __):
        reader = mocker.patch("asyncio.StreamReader")
        writer = mocker.patch("asyncio.StreamWriter")
        mocker.patch.object(reader, "readexactly", _mock_read)
        return reader, writer

    config = DeviceConfig("127.0.0.1")
    protocol = TPLinkSmartHomeProtocol(transport=_XorTransport(config=config))
    mocker.patch("asyncio.open_connection", side_effect=aio_mock_writer)
    response = await protocol.query({})
    assert response == {"great": "success"}
    if log_level == logging.DEBUG:
        assert "success" in caplog.text
    else:
        assert "success" not in caplog.text


@pytest.mark.parametrize("custom_port", [123, None])
async def test_protocol_custom_port(mocker, custom_port):
    encrypted = TPLinkSmartHomeProtocol.encrypt('{"great":"success"}')[
        TPLinkSmartHomeProtocol.BLOCK_SIZE :
    ]

    async def _mock_read(byte_count):
        nonlocal encrypted
        if byte_count == TPLinkSmartHomeProtocol.BLOCK_SIZE:
            return struct.pack(">I", len(encrypted))
        if byte_count == len(encrypted):
            return encrypted
        raise ValueError(f"No mock for {byte_count}")

    def aio_mock_writer(_, port):
        reader = mocker.patch("asyncio.StreamReader")
        writer = mocker.patch("asyncio.StreamWriter")
        if custom_port is None:
            assert port == 9999
        else:
            assert port == custom_port
        mocker.patch.object(reader, "readexactly", _mock_read)
        return reader, writer

    config = DeviceConfig("127.0.0.1", port_override=custom_port)
    protocol = TPLinkSmartHomeProtocol(transport=_XorTransport(config=config))
    mocker.patch("asyncio.open_connection", side_effect=aio_mock_writer)
    response = await protocol.query({})
    assert response == {"great": "success"}


def test_encrypt():
    d = json.dumps({"foo": 1, "bar": 2})
    encrypted = TPLinkSmartHomeProtocol.encrypt(d)
    # encrypt adds a 4 byte header
    encrypted = encrypted[4:]
    assert d == TPLinkSmartHomeProtocol.decrypt(encrypted)


def test_encrypt_unicode():
    d = "{'snowman': '\u2603'}"

    e = bytes(
        [
            208,
            247,
            132,
            234,
            133,
            242,
            159,
            254,
            144,
            183,
            141,
            173,
            138,
            104,
            240,
            115,
            84,
            41,
        ]
    )

    encrypted = TPLinkSmartHomeProtocol.encrypt(d)
    # encrypt adds a 4 byte header
    encrypted = encrypted[4:]

    assert e == encrypted


def test_decrypt_unicode():
    e = bytes(
        [
            208,
            247,
            132,
            234,
            133,
            242,
            159,
            254,
            144,
            183,
            141,
            173,
            138,
            104,
            240,
            115,
            84,
            41,
        ]
    )

    d = "{'snowman': '\u2603'}"

    assert d == TPLinkSmartHomeProtocol.decrypt(e)


def _get_subclasses(of_class):
    import kasa

    package = sys.modules["kasa"]
    subclasses = set()
    for _, modname, _ in pkgutil.iter_modules(package.__path__):
        importlib.import_module("." + modname, package="kasa")
        module = sys.modules["kasa." + modname]
        for name, obj in inspect.getmembers(module):
            if inspect.isclass(obj) and issubclass(obj, of_class):
                subclasses.add((name, obj))
    return subclasses


@pytest.mark.parametrize(
    "class_name_obj", _get_subclasses(TPLinkProtocol), ids=lambda t: t[0]
)
def test_protocol_init_signature(class_name_obj):
    params = list(inspect.signature(class_name_obj[1].__init__).parameters.values())

    assert len(params) == 2
    assert (
        params[0].name == "self"
        and params[0].kind == inspect.Parameter.POSITIONAL_OR_KEYWORD
    )
    assert (
        params[1].name == "transport"
        and params[1].kind == inspect.Parameter.KEYWORD_ONLY
    )


@pytest.mark.parametrize(
    "class_name_obj", _get_subclasses(BaseTransport), ids=lambda t: t[0]
)
def test_transport_init_signature(class_name_obj):
    params = list(inspect.signature(class_name_obj[1].__init__).parameters.values())

    assert len(params) == 2
    assert (
        params[0].name == "self"
        and params[0].kind == inspect.Parameter.POSITIONAL_OR_KEYWORD
    )
    assert (
        params[1].name == "config" and params[1].kind == inspect.Parameter.KEYWORD_ONLY
    )